Stayed 5 nights over Christmas and it was fantastic. The location is close to everything - just a short walk to Chong Nonsi BTS station or a little further to Sala Daeng. In the centre of Silom with lots of great places to eat and nightlife to enjoy.
The apartment I stayed in was 5105 I think, on the 5th floor and it overlooked the pool. A compact set up but with everything you could need including a washing machine - which is nice when the days are still hot and humid and having the chance to wash clothes is a bonus. Everything worked fine so there was no need to contact the owner at any time during my stay.
Check in was super easy, and checkout was just as smooth. I travelled in and out by public transport (Airport rail link and BTS) and it was pretty straightforward and easy although there was a little bit of crowding on the BTS on the morning I left - but definitely doable and only about 80 Baht and an easy 45/50 mins yo there airport even in peak hour.
Will definitely look to stay here again next time I'm in Bangkok